Re: BTRFS constantly reports "No space left on device" even with a huge unallocated space
From: Ronan Arraes Jardim Chagas <hidden>
Date: 2016-08-30 16:57:51
Em Ter, 2016-08-30 às 10:44 -0600, Chris Murphy escreveu:
It sounds related to read-only snapshots to me. I wonder if this system has something busy that's writing to a file, database, even maybe something just spamming journald, and then there's a read-only snapshot during the write, which then triggers the enospc.
I saw the problem yesterday after lunch time (13:00) and the last snapper snapshot was taken at 10:17: snapper list Tipo | # | Pre # | Data | Usuário | Limpeza | Descrição | Dados de usuário -------+----+-------+------------------------------+----------+------ ---+-----------------------+------------------ single | 0 | | | root | | current | single | 1 | | Ter 16 Ago 2016 15:07:25 BRT | root | | first root filesystem | single | 2 | | Ter 16 Ago 2016 15:15:57 BRT | root | number | after installation | important=yes pre | 4 | | Ter 16 Ago 2016 15:26:44 BRT | root | number | zypp(y2base) | important=yes post | 5 | 4 | Ter 16 Ago 2016 16:12:46 BRT | root | number | | important=yes pre | 29 | | Ter 16 Ago 2016 18:02:43 BRT | root | number | zypp(zypper) | important=yes post | 30 | 29 | Ter 16 Ago 2016 18:07:34 BRT | root | number | | important=yes pre | 45 | | Seg 22 Ago 2016 13:59:45 BRT | root | number | zypp(zypper) | important=yes post | 46 | 45 | Seg 22 Ago 2016 14:11:17 BRT | root | number | | important=yes pre | 89 | | Seg 29 Ago 2016 09:56:19 BRT | root | number | yast sw_single | pre | 90 | | Seg 29 Ago 2016 10:00:00 BRT | root | number | zypp(y2base) | important=no post | 91 | 90 | Seg 29 Ago 2016 10:01:11 BRT | root | number | | important=no pre | 92 | | Seg 29 Ago 2016 10:07:01 BRT | root | number | zypp(y2base) | important=no post | 93 | 92 | Seg 29 Ago 2016 10:07:10 BRT | root | number | | important=no pre | 94 | | Seg 29 Ago 2016 10:12:32 BRT | root | number | zypp(y2base) | important=no post | 95 | 94 | Seg 29 Ago 2016 10:14:25 BRT | root | number | | important=no post | 96 | 89 | Seg 29 Ago 2016 10:17:17 BRT | root | number | |
Ronan, if you're given a work around, then it's even less likely the bug gets fixed. But if you can disable snapper snapshots entirely and the problem doesn't happen; or if you can increase the frequency of snapper snapshots and the problem happens more often, that might help narrow it down to a point where it's more easily reproduced. If it's not related, that's still useful to know.
I agree with you. The problem is that since this is a production machine, it is kind very problematic to have so many reboots that occurs randomly. I will install something using zypper, which will trigger snapper, and see if the problem will be triggered. I will be out of the office this afternoon, so the machine will be on idle. Best regards, Ronan Arraes